Ram truck

ABSTRACT

909,282. Fork lift trucks. YALE &amp; TOWNE MANUFACTURING CO. Sept. 15, 1960 [Dec. 10, 1959], No. 31759/60. Class 78 (3). The tines 16, 17 of a fork lift truck can be adjusted transversely of the truck to facilitate loading of a pallet, and can be juxtaposed to form a single load engaging member for lifting a coil. The tines 16, 17 are pivoted at 35 to members 19, 20 which are movable transversely across the lifting carriage 11 by means of independent operation of hydraulic rams 26, 27 in opposed directions. Each tine is secured to a plate 34 provided with lugs 39 guided by tracks 40, 45, 47 which guide the tines for parallel lateral adjustment and which tilt the tines to the chain line coil lifting position when they are moved into juxtaposed position and coact with the track 47. The tracks 40 are formed on the lower edge of a plate 41 secured to the truck, and the tracks 45, 47 on a cam plate 43 which is slidable transversely of the truck in a mounting 44 and arranged behind a cut-away portion of the plate 41. When the tines are juxtaposed to form a single loadengaging member, the position of this member relative to the truck can be varied by operating the rams in the same direction, the plate 43 then sliding in its mounting.

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IN V EN TOR. AM as M L EEPEI? United States Patent 3,033,402 RAM TRUCK James W. Leeper, Philadelphia, Pa., assignor to The Yale and Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Filed Dec. 10, 1959, Ser. No. 858,634 8 Claims. (Cl. 214-731) This invention relates to an industrial lift truck having load members that can be juxtaposed to form a single lifting ram, or that can be separated whereby to form two rams or load forks.

A truck of that kind is shown in the earlier patent to Charles S. Schroeder, No. 2,676,723. In that truck, there are two complementary ram sections that can be juxtaposed to form a single ram that will have a substantially continuous curved load surface, and that may be inserted into an opening in a coil in position to lift the coil. Because the curved surface is substantially continuous, the ram is not likely to damage the load and can be used effectively for lifting rather heavy coils of tin plate. When the sections of the ram are separated, they will present individual curved surfaces that can be used for lifting two coils. The Schroeder construction has been commercially successful, but it has been found that more versatile equipment now is needed to meet the requirements of the industry.

Thus, in the load handling methods that have now been developed, it frequently is necessary to handle each load through the successive use of a pair of separate ram sections or forks, and then a single ram. For example, a truck may be required first to use the separated sections to lift a pallet on which is a coil of steel strip, and then to use the sections as a single ram to lift that coil without the pallet. To do that effectively, it is necessary that the truck operator have better control of the ram or fork sections so that he can more easily adjust them to particular positions. I achieve that control through the novel concept of my invention, while also retaining the very desirable advantages of the Schroeder patent.

In my invention, I mount a pair of ram sections for individual movement on the lifting carriage of a truck, with each section adapted to move in a linear horizontal direction and also to rotate on its individual mounting. Each ram section is relatively thin in a vertical direction, and has a load surface that will be presented upwardly when the sections are horizontally separated. The sections then can be used as forks to handle a pallet that has low underclearance. When the ram sections are moved on their mountings into juxtaposed relation to one another, they will rotate to form a single ram, with their load surfaces in effect forming one continuous lifting surface.

Thus, by moving the ram sections in linear directions toward and away from one another, they will be adjusted for handling a pallet or coil. Those linear movements, with independent vertical adjustment of the lifting carriage of the truck, will enable the truck operator to have very effective control of the ram sections, so that he will find it easy to place the sections in the exact positions to engage the pallet or coil. Moreover, by their horizontal movement the ram sections can be separated different distances for insertion under pallets of different sizes, despite the fact that the pallets may have low underclearance.

As a particular feature of my invention, I utilize cam means to control the rotation of the ram sections on their mountings. Those cam means will act automatically when the sections move into juxtaposed relation to one another, whereby to rotate the sections into position forming a single ram. When the ram sections are separated,

the cam means will act immediately as the sections start to move out of juxtaposed relation to rotate the sections so as to present their load surfaces in an upward direction. The sections then can be adjusted horizontally to any position that may be desired for handling a particular pallet or load, while each load surface remains upwardly presented to coact with the load.

As a further feature, I so arrange my cam means as to allow bodily side shifting of both ram sections. To do that, I utilize a cam plate that can move with the sections as they move horizontally. The ram sections will be rotated and held rotated through contact with the cam plate when in their juxtaposed single ram position, but the sections nevertheless can be side shifted bodily because the cam plate can move with the sections. A side shifting movement of the ram sections can also be achieved when the sections are in separated positions, while a part of the cam means holds the sections so that they do not rotate.

The side shifting feature of my invention is in itself of considerable assistance in performing the handling methods to which I have referred. Thus, for example, when the truck sets down a pallet on which is a coil, the side shifting will facilitate the exact placing of the pallet. Then, when it is desired to pick up the coil on the ram, it may be found that the coil opening is not in position to align with the ram. However, particular maneuvering of the truck will be unnecessary, since the ram can easily be side shifted to align with the coil opening. Thereby I am able to perform the handling operation with better efiiciency.

I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows may be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto.

Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of my invention, in order to prevent the appropriation of my invention by those skilled in the art.

Referring now to the drawings,

FIG. 1 shows a side view of a lift truck utilizing my novel ram assembly;

FIG. 2 shows a front view of my invention;

FIG. 3 is a section on the line 33 in FIG. 2;

FIG. 4 shows a side shifted position of the ram sections when forming a single ram;

FIG. 5 shows the sections side-shifted while separated to act as two forks or load members;

FIG. 6 shows the ram sections separated a relatively short distance for 'coacting with a narrow pallet.

Referring now more particularly to FIG. 1 of the drawings, I indicate the ram assembly of my invention generally by the numeral 10, and show that assembly mounted on a load carriage 11 at the front of a lift truck T. The load carriage 11 has rather usual roller brackets 12 through which it is mounted for lifting movement on uprights 13 on the truck T, the lifting movement being effected through lifting means 14, as will be understood by those persons skilled in the art. The details of the truck T are not important to an understanding of my invention, but it will be noted that the truck has controls 3 truck operator to control the truck and the handling of a load on the carriage 11.

My novel ram assembly utilizes a pair of load engaging complementary ram sections 16, 17 that are well shown in FIGS. 1 and 2. Each ram section 16, 17 has a curved lifting surface 18 that will be presented upwardly when the sections are separated, as shown in full lines in FIG. 2. The sections 16, 17 are adapted to be juxtaposed and rotated, as shown in dot-and-dash lines in FIG. 2, so as to form a single ram with both lifting surfaces 18 providing a substantially continuous load lifting surface for that ram. Thus, it will be seen that the ram sections 16, 17 are somewhat like those shown in the Schroeder patent, to which I have already referred. In my invention, how ever, the ram sections or forks 16, 17 and their actuating means do have exceedingly novel features that are important, as will appear.

To support the sections or forks 16, 17, I utilize a pair of individual mounting members 19, 20, shown in FIGS. 2 and 3. Each mounting member 19, 20 is arranged vertically at the front of a carrier plate 21 that forms a part of the truck carriage 11, and has a bracket 22 that slides on the upper edge of the carrier plate 21. A lower portion of each mounting member 19, 20 slides on a bearing or Wear plate 23 on the carrier plate 21, as will be understood from FIG. 3. I prefer to equip each mounting member 19, 20 with a portion 24 acting as a guide in a slot in carrier plate 21, and a clip 25 that holds the member assembled to the lower edge of plate 21. Thereby the carrier plate 21 supports each individual mounting member 19, 20 for horizontal linear sliding in a transverse direction relatively to the truck.

Merely for purposes of disclosure, I show a pair of hydraulic rams 26, 27 for individually sliding the mounting members 19, 20 on carrier plate 21. As is best seen in FIG. 2, one end of ram 26 is attached to a bracket 28 on a side portion 29 of the truck carriage 11, with the opposed end of ram 26 attached to the mounting member 19 through a bracket 30. Similarly, opposed ends of ram 27 are attached through a bracket 31 to a side portion 32 of the carriage, and through a bracket 33 to the mounting member 20. Thus, by actuating hydraulic rams 26, 27 in appropriate directions, the mounting members 19, 20 will be moved either in unison, or relatively to one another. I prefer to enclose the hydraulic rams 26, 27 through a front plate 41 that is secured to the carriage side portions 29, 32.

I make each of the load ram sections 16, 17 of my invention relatively thin in a vertical direction, and I form each section with a base portion 34 having on its rear face a shaft 35, each shaft 35 being supported through a bearing 36, one of which is shown in FIG. 3, whereby to rotate on the corresponding mounting member 19 or 20. The arrangement in my preferred construction is such that each ram section 16, 17 will rotate about an axis that is substantially in its load surface 18, as will be appreciated when considering FIG. 2. Each ram section 16, 17 is further supported on its corresponding mounting member 19, 20 through a lower bearing plate 36a, FIG. 3, and a guide 37 that is engaged over a curved upper part 38 on the base 34 of that section.

I now call attention to the fact that the base 34 of each ram section has a pair of transversely spaced lugs 39, FIG. 2. Those lugs 39 are adapted to slide in contact with transverse surfaces 40 formed on a part of the truck carriage 11, as on the lower edge of front plate 41. When the mounting members 19, 20 are in separated positions, or in other words when each ram section 16, 17 is positioned toward a side of the truck, as shown in full lines in FIG. 2, the surfaces 40 will coact with the lugs 39 to hold the ram sections 16, 17 against rotation, and with their lifting surfaces 18 presented upwardly.

Also, I cut away a medial portion 42 of plate 41 whereby to form clearance for one lug 39 on each ram section 16, 17 when the sections move on their mountings toward the center of the truck. Thereby the cut away portion 42 may allow the ram sections 16, 17 to rotate on their mountings, but I particularly control that rota tion through a cam plate 43, FIGS. 2 and 3. The cam plate 43 is arranged behind the cut away portion 42 of front plate 41, and is mounted to slide in a transverse direction, as through a guide 44 on plate 41. I form the cam plate 43 with edge portions 45 that in effect are continuations of the surfaces 40 on plate 41, and with a medial part 46 that extends downwardly beyond the edge portions 45. At each side of its downwardly extending medial part 46, the cam plate 43 has an opening 47 that is adapted to accept one lug 39 on the base of a ram section 16, 17.

As the ram sections 16, 17 move toward one another from their full line separated positions in FIG. 3, one lug 39 on each section 16, 17 will leave the surface 40, but will then move along the edge portion 45 on cam plate 43. Thus, the ram sections 16, 17 can move horizontally to different separated positions relatively to one another, yet those sections will be held against rotation and with their lifting surfaces 18 presented upwardly. When the ram sections 16, 17 actually move into juxtaposed relation, surfaces 48 on the base of each section will engage the medial part 46 on cam plate 43, so that the sections 16, 17 will rotate into their single ram position as shown in dot-and-dash lines in FIG. 2, their surfaces 18 then presenting a substantially continuous curved load surface. It will be seen that one lug 39 on each ram section 16, 17, when in single ram position, will lie in one of the openings 47 on cam plate 43. Thus, upon separating movement of the sections, cam plate 43 will immediately act to rotate the sections back so as to present each load surface 18 separately in an upward direction.

It is important to realize also that the cam plate 43, by sliding on its mounting 44, will effectively control the rotation of the ram sections 16, 17, even though the sections are not centered relatively to the truck. Also, cam plate 43 will slide to allow side shifting of the ram sections while the sections are in a juxtaposed single ram position.

My invention may be more fully understood if we review the operation of the ram sections. Let us assume that the ram sections 16, 17 are first in the full line positions shown in FIG. 2, and are moved toward juxtaposed relation to one another. It will be seen that the lugs 39 will at first slide along the surfaces 40 on plate 41, and also along the surfaces 45 on cam plate 43, thus effectively holding the ram sections with their thin dimension vertical and with their lifting surfaces 18 in upwardly presented position. Now, if the movement is continued so as to juxtapose the sections 16, 17, one lug 39 on each section will move against the medial part 46 on cam plate 43, as shown in FIG. 6, causing the sections 16, 17 to rotate to the position shown in dot-and-dash lines in FIG. 2.

It will thus be seen that the ram sections 16, 17 have moved in a linear horizontal direction while moving into juxtaposed relation to one another, and have rotated to their single ram position merely at the end of their linear movement. By stopping the linear movement of the sections 16, 17 at any desired point, those sections will be in position to coact with a pallet of a particular width. By continuing the movement, the sections will form a single ram that is adapted to lift a coil.

If the ram sections 16, 17 are later moved to separated positions, the cam plate 43 first will act against the lugs 39 that are in the openings 47, thus rotating the ram sections 16, 17 to place their lifting surfaces 18 in upwardly directed position, as shown in FIG. 6. Further separating movement of the sections 16, 17 will take place in a linear horizontal direction, with their surfaces 18 upwardly presented throughout that movement.

Of course, the movements that I have just described will be achieved through simultaneous actuation of-the hydraulic rams 26, 27 in opposed directions. I shall now explain the particular operation of my invention when the hydraulic rams 26, 27 are actuated in the same direc tion to effect side shifting. Thus, let us first assume that the load ram sections or forks 16, 17 are in their juxtaposed single ram position that is shown in dot-and-dash lines in FIG. 2. Now, if ram sections 16, 17 are bodily side shifted to the position shown in FIG. 4, for example, the cam plate 43 will slide on its mountingso as to move along with those sections. Therefore, despite the side shifting of the ram sections 16, 17, the cam plate 43 will still be in position to control rotation of the sections in the manner 1 have earlier described. Naturally, it will be possible to side shift the ram sections or forks 16, 17 when they are in separated positions such as those shown in FIGS. and 6, since the cam plate 43 can move along with one or both of the sections. If one section is held still, cam plate 43 can be moved by the other section and will rotate both sections.

Because I move my ram sections 16, 17 in a linear horizontal direction, I can very readily adjust those sections to positions for handling pallets that may have low under clearance. Thus, for example, in adjusting the sections 16, 17 between the separated position shown in full lines in FIG. 2 and the FIG. 5 or FIG. 6 position, the sections will have no vertical component of move ment, and in any of those positions can be placed very close to the ground; Moreover, since the sections do not then rotate, their load surfaces 18 will remain in a position presented upwardly to coact with a pallet. In addition, I enable vertical adjustments of the ram sections 16, 17 to be controlled always through vertical actuation of the truck carriage 11. Thereby I simplify to a great extent the positioning of the sections relatively to the pallet or other load, whether the sections are separated or in their juxtaposed single ram position.

I believe that the construction and operation of my novel lifting ram assembly will now be fully understood, and that the very considerable value of my invention will be appreciated by those persons skilled in the art.

I now claim:

1. In a truck of the class described, a carriage mounted for lifting movement on the truck, a pair of load engaging members moving vertically with said carriage and having each a load lifting surface, a mounting member supporting each individual load engaging member for movement independently of the other in a transverse direction on said lifting carriage, means mounting each load engaging member for rotation relatively to the carriage, a cam member against which portions on said load engaging members move when said members move into juxtaposed positions relatively to one another on their mountings so as to rotate the members, said members then forming a single ram with the load lifting surface on each load engaging member providing in conjunction with the load lifting surface on the other member a substantially continuous load lifting surface on the single ram, means mounting said cam member for movement with said load engaging members in a transverse direction on said carriage whereby to enable those members to be bodily side shifted when in single ram position, and surfaces on said cam means acting when said load engaging members move away from their said juxtaposed position to rotate those members whereby to place their load lifting surfaces in position for handling a pallet.

2. In a truck of the class described, a carriage mounted for lifting movement on the truck, a pair of loadengaging members moving vertically with said carriage and having each a load lifting surface, a mounting member supporting each individual load-engaging member for linear movement in a horizontal direction toward and away from the other load-engaging member on said lifting carriage, means supporting each load-engaging member for rotation on its mounting member, a cam plate having a part against which portions on said loadengaging members impinge when moving horizontally into juxtaposed positions relatively to one another on their mountings whereby to rotate the members into position forming a single ram, the load lifting surface on each load-engaging member then providing in conjunction with the load lifting surface on the other load engaging member a substantially continuous and upwardly presented load lifting surface on the single ram, means mounting said cam plate for movement with said load-engaging members to enable those members to be bodily side shifted when intheir single ram position, and surfaces on said cam plate coacting with the load-engaging members to rotate those members as they move away from their said juxtaposed position whereby to present upwardly the load lifting surface on each of those members, so that the load lifting surfaces will be in position for handling a pallet when the load-engaging members are adjusted to different separated positions for handling pallets of different widths, and when those members are bodily side shifted on their mountings.

3. In a truck of the class described, a carriage mounted for lifting movement on the truck, a pair of load-engaging members moving vertically with said carriage and having each a curved load lifting surface, a mounting member supporting each individual load-engaging member f r linear movement in a horizontal direction toward and away from the other load-engaging member on said lifting carriage, means supporting each load-engaging member for rotation on its individual mounting member, a cam plate having opposed surfaces against which portions on said load-engaging members impinge when moving horizontally into juxtaposed positions relatively to one another on their mountings whereby to rotate the members into position forming a single ram, the curved load lifting surface on each individual load-engaging member then providing in conjunction with the curved load lifting surface on the other load-engaging member a substantially continuous curved and upwardly presented load lifting surface on the single ram, means mounting said cam plate for transverse movement on the truck carriage, so as to enable said cam plate to move with one or both loadengaging members when moved horizontally on the can riage, surfaces on said cam plate coacting with the loadengaging members to rotate those members as they move away from their said juxtaposed position whereby to present upwardly the curved load lifting surface on each of those members, and parts on said carriage formed with surfaces holding the load-engaging members against rotation when they are in different separated positions on the carriage, so as to hold the curved load lifting surfaces in upwardly presented position when the load-engaging members are adjusted for handling pallets of different widths, and when those memberes are bodily side shifted on th ir mountings.

4. In a truck of the class described, a carriage mounted for lifting movement on the truck and having a carrier member, a pair of fork mounting members supported for movement in a transverse direction on the carrier member of said carriage, a load fork having a base portion mounted for rotation on each fork mounting member and movable transversely with said member, a control part mounted on the carrier member and extending in juxtaposed relation to the base portion of each load fork, the base portion of each fork moving relatively to said juxtaposed control part as the fork moves transversely with its mounting member, and means on said base portions and the juxtaposed control part coacting to rotate said 'base portions when said portions move transversely relatively to said part, whereby to change automatically the angular position of each load fork when the fork moves in a transverse direction relatively to the carriage.

5. In a truck of the class described, a carriage mounted for lifting movement on the truck, a pair of load engaging members moving vertically with said carriage and having each a load lifting surface, a mounting member supporting each individual load engaging member for linear movement in a horizontal direction relatively to the other load engaging member on said lifting carriage, means mounting each load engaging member for rotation relatively to the carriage, cam means on said carriage, surfaces on said cam means coacting with portions on said load engaging members as said members move into juxtaposed positions relatively to one another on their mountings to rotate the load engaging members, said load engaging members then forming a single ram with the load lifting surface on each load engaging member providing in conjunction with the load lifting surface on the other load engaging member a substantially continuous load lifting surface on the single ram, surfaces on said cam means acting when said load engaging members move away from their said juxtaposed position to rotate those members whereby to present their load lifting surfaces for coacting with a pallet, and said load lifting surfaces adapted by the horizontal direction of movement of the load engaging members on their mountings to be placed in positions to handle pallets of different widths.

6. In a truck of the class described, a carriage mounted for lifting movement on the truck, a pair of load engaging members moving vertically with said carriage and having each a curved load lifting surface, mounting members supporting said load engaging members for linear movement in a horizontal direction between separated and juxtaposed positions relatively to one another on said lifting carriage, means mounting each load engaging member for rotation relatively to the carriage, cam means on said carriage, surfaces on said cam means coacting with portions on said load engaging members as said members move to their said juxtaposed positions to rotate the load engaging members, said load engaging members then forming a single ram with the load lifting surface on each load engaging member providing in conjunction with the load lifting surface on the other member a substantially continuous curved and upwardly presented load l ing surface on the single ram, surfaces on said cam means acting when said load engaging members move away from their said juxtaposed position to rotate those members whereby to present upwardly the load lifting surface on each load engaging member, and parts on said carriage formed with surfaces coacting with the load engaging members to prevent rotation of those members as they move to their said separated positions, so as to hold the load lifting surfaces upwardly presented for handling a pallet.

7. In a truck of the class described, a carriage mounted for lifting movement, a pair of load engaging forks, mounting members supporting said forks for horizontal sliding relatively to one another in a linear direction on said carriage, means mounting each fork for rotation relatively to said carriage on an axis extending perpendicularly relatively to said line, each fork being shaped with a longitudinal thin portion adapted for engagement with a pallet having low underclearance when the fork is in one rotated position on its mounting, cam means on said carriage, surfaces on said cam means coacting with parts on the forks to place said forks in a second rotated position when they move into juxtaposed relation to one another on their mountings, and the shape of said longitudinal fork portions contributing complementary curved lifting surfaces that are effective when the forks are in their second rotated position to form a ram with a substantially continuous curved lifting surface.

8. In a truck of the class described, a carriage mounted for lifting movement, a pair of load engaging forks so shaped that each has a relatively thin longitudinal portion, mounting members supporting said forks for horizontal sliding between separated and juxtaposed positions relatively to one another in a linear direction on said carriage, means mounting each fork for rotation relatively to said carriage on an axis extending perpendicularly relatively to said line, said carriage having cam surfaces coacting with portions on the forks when the forks are in separated positions to hold each fork in one rotated position with its thin dimension vertical, whereby said forks are adapted for engagement with a pallet having low underclearance, a cam on said carriage, said cam having surfaces coacting with parts on the forks to place said forks in a second rotated position when they move into juxtaposed positions, the shape of said forks contributing complementary curved lifting surfaces that act when the forks are in their second rotated position to form in effect a single lifting ram, and means mounting said cam to move with said forks when they are in their second I'0- tated position, whereby to allow bodily side shifting of the ram while the lifting surfaces of the forks provide a substantially continuous curved lifting surface on the ram.

References Cited in the file of this patent UNITED STATES PATENTS 2,671,571 Gerhardt Mar. 9, 1954 2,676,723 Schroeder Apr. 27, 1954 

